We report measurements of kaon electroproduction from a hydrogen target carried out at DESY. The invariant cross section for the reaction ep → eK+ + anything is given as a function of the variables q2, W, x, p2⊥ and φ in the following region: −0.5 ⩽ q2 ⩽ −0.1 GEV2, 2.0 ⩽ W ⩽ 2.8 GEV, 0.3 ⩽ x ⩽ ⩽ 1.0, p2⊥ ⩽ 0.25 GEV2, 0° ⩽ ø ⩽ 360°. Finally we compare our data with a quark-parton model.

We report on the measurement of the process e + p → e + p + π0 at energies above the resonance region. The pions are predominantly produced perpendicular to the electron scattering plane. The cross section shows a dip at the minimum momentum transfer. Both features are expected from comparison with photoproduction.

We report on an experiment where the different contributions from the transverse and longitudinal polarization of the virtual photon are measured separately for the reaction e−p→e−π+n. The data taken above the resonance region at small ∣t∣ values in the q2 range of ∣q2∣ < 0.5 GeV2 show a clear dominance of the longitudinal part of the cross section and are well described by a generalized Born-term model. Using this model the electromagnetic form factor of the pion is determined. At q2 = −0.35 GeV2 one gets Fπ = 0.598 ± 0.021.

In this paper data on the inclusive reaction e−p→e−p+ anything as obtained in a coincidence experiment at DESY are presented. The invariant cross section is given as a function of q2, W, x, p⊥2 and φ in the following kinematical region: −0.64<q2 <−0.08 GeV2, 1.96<W <2.80 GeV, 0 <x < 1, 0 <p⊥2 < 0.29 GeV2, 0° <φ <360°. The inclusive spectra are compared with the results from photoproduction and other electroproduction experiments.

The electroproduction of K+Y on protons, ep→ek+Y, (Y≡Λ; Σ0; Σ′0 (1385); Λ′(1405); Λ′(1520)) was investigated by measuring the scattered electron and the produced K+ meson in coincidence. The differential cross sections were determined as functions of W, q2, t and φKγ in the kinematical region: 1.9 ⩽ W ⩽ 2.8 GeV−0.10 ⩾q2 ⩾−0.60 GeV2/c2tmin⩾t ⩾tmin−0.33GeV2/c2, 0 ⩽ φKγ ⩽ 360°.

We investigate thes inclusive pion spectra in the electroproduction reaction ep → eπ±+ anything in a coincidence experiment at DESY. Data are presented from the kinematical region 0.1 < |q2| < 0.8 GeV2 and 3.15 < W < 2.8 GeV as a function of the transverse momentum squared pT2, the Feynman variable x2, and the azimuth angle φ. The charge ratio π+π− is given in terms of the variables q2 and x. The inclusive spectra are compared with results from photoproduction.

The electroproduction of a π-meson and of a Δ(1236) nucleon resonance on hydrogen, ep → eπΔ (1236), was investigated in the two charge states π−Δ++ and π+Δ0 by measuring the scattered lepton and the produced π-meson in coincidence. The differential cross sections as funcions of W, q2, t−tmin and øπq were determine in the following kinematical region: w = (π + δ)2 = 2.0 − 3.0 GeV, |q2| = |(e−e′)2 | = 0.15 − 0.8 GeV2/c2, |t − tmin| = 0-0.5GeV2/c2 with t = (p − δ)2, φπq = 0 − 360°.

Electroproduction of the vector mesons π0 and Ω on protons at backward angles was investigated by measuring the scattered electron and the recoiling proton in coincidence. The differential cross section was determined as function of W, q2, u−umin and ϕV in the following kinematical region: 1.9 ⩽ W ⩽ 2.6 Gev, 0.1 ⩽ |;q2| ⩽ 0.9 GeV2/c2, −0.13 ⩽ u−umin ⩽0 GeV2/c2, 00 ⩽ ϕV ⩽ 360°.

The electroproduction of transversely polarized ϱo-mesons on protons has been measured detecting the scattered electron and the two decay π-mesons in spark-chamber spectrometers. The differential cross sections dσu/dt and dσu/d(t–tmin) have been determined as functins of W, q2 and t and W, q2 and t−tmin in the kinematical region 2.60 ⩽ W ⩽ 2.95 GeV, −0.12 ⩾ q2 ⩾ −0.40 GeV2/c2, tmin⩾ t ⩾ −0.15 GeV2/c2.

The electroproduction of a π+ meson and of the Δ0(1236) nucleon resonance on hydrogen, ep→e'π+Δ0(1236), was investigated by measuring the scattered electron and the produced π+ meson in coincidence. The differential cross sections as functions of so, q2, t−tmin or θπq+, and φπq were determined in the following kinematical region: so = (π+ + Δo)2 = 4.4−6.3 GeV2, |q2| = |(e−e')2| = 0.2−0.8 GeV2/c2, |t−tmin| = 0−0.1 GeV2/c2, θπq∗ = 0o–20o, φπq = 0−360o.

The electroproduction of single π+ − mesons on hydrogen, e + p → e′ + π+ + n, has been measured up to values of |q2| ⩽ 0.9 GeV2/c2. The differential cross sections have been determined for small momentum transfer to the nucleon over the full azimuthal angle Øπq.

The longitudinal contribution σL to the cross section for electroproduction of π+ -mesons on protons has been determined from the measured values of 12(σ∥ + σL) + ϵ σL assuming the ratio σ∥/σL ⩽ 0.1 for 0.02 ⩽|t| ⩽ 0.15 (GeV/c)2, as is known from the photoproduction of π+ -mesons.